The present invention relates to method and apparatus for generating patterns for building materials, interior finishing materials and exterior facing materials which are arranged side by side in a plane, such as tiles, wall paper and tile carpets.
In the case of tiles and similar industrial products, printing patterns on them is important for increasing their value. Incidentally, if patterns on adjacent tiles arranged side by side on a wall surface are smoothly continuous with each other across the boundary of the tiles without making the boundary noticeable, the patterns would be seen as if it were a single smooth pattern spreading over the entire wall area. Furthermore, when tiles with the same pattern (a basic tile pattern) are merely arranged in the same orientation, the same pattern variation repeatedly appear every tile; hence, the tiles individually stand out for each pattern. When tiles are laid in different orientations or a small number of tiles with different patterns are laid, if the patterns can be made to continue across the boundaries of the tiles, their appearance is improved since they can be regarded as a single pattern.
Moreover, it would be preferable from the viewpoint of increasing diversity of tiles if plural kinds of tiles, which have patterns continuous with each other across the boundaries of adjacent tiles and have different patterns in marginal areas, can be laid in a plane in a random combination. Aside from the formation of simple geometric patterns or manual drawing of approximate patterns, however, it is difficult to generate a plurality of patterns which continue across the boundaries of them. Besides, it is only about two kinds of such patterns that can be generated, and the boundary of the tiles somehow appears; hence, at least four kinds of basic tile patterns are required. However, the preparation of tiles each having a plurality of patterns present problems in terms of mass-producing cost, distribution cost and complexity of handling.